MPs have been warned to take safety precautions as riots continue to spread across the country.
Members of parliament have been urged to contact police and consider working from home instead of their constituency offices.
Those whose offices are “prominent and easily identifiable” have also been advised to look at their security protocols.
And MPs near where 30 protests are planned on Wednesday have also been made aware of the situation.
The warning comes in a letter to MPs by the Commons Speaker Lindsay Hoyle.
Almost 400 people have now been arrested over the mob violence amid appalling scenes.
On Monday night police were injured during “sustained violence” in Plymouth, while similar trouble on the streets of Darlington saw officers pelted with bricks.
There was also unrest on the streets of Belfast.
Thousands of specialist police officers have been placed in a new ‘standing Army’ ready to deal with the rioting. Keir Starmer has announced.
Courts could also begin sitting through the night to process the accused, a minister has suggested.
There are fears of at least 30 possible protests on Wednesday according to information circulating online.
In the letter Speaker Hoyle tells MPs he has no information that they or their offices are targets.
He adds: “However, we note the spontaneity and unpredictable nature of the disorder and would therefore encourage Members and their offices to exercise caution.”
“Publicly available information suggests that a range of locations associated with immigration and asylum assistance are due to be subject to demonstrations on Wednesday 7 August at 8pm. The Parliamentary Security Department (PSD) have reached out to Members who have offices in close proximity to these planned demonstrations, to make them aware.”
Other MPs “particularly those with prominent and easily identifiable office locations – may wish to consider their office security protocols” he writes.
These can include talking to their local police force “to gain an up to date understanding of the risks and policing plans in your area; considering home working; and ensuring that any sensitive information is stored safely”.
He adds: “In the event of an emergency, don’t hesitate to call 999.”